Boiler furnace



(No Model.) 3 Sheets-Sheet 2.

I. BOWB.

- BOILER FURNAGE. 10.371,872.- Patented oct. 18, 1887.

(No Model.) 3 Sheets-Sheet 3.

1. BOWB.

BOILBR FURNACE.

Patented Oct. 18, 1887.

fits/'em E r.'

Unirse tirarse ISAAC BOWE, OF CHICAGO, ILLINOIS,ASSIGNOR OF ONE-II ALF TO `GEORGE A. GINDELE, OF SAME PLACE.

BOlLER-FURNACE.

SPECIFICATION forming part of Letters Patent No. 371,872, dated October 18, 1887.

Application filed il1'ay24, 1887. Serial No. 239,187. (No model.)

To all whom it may concern.-

Beit known that I, ISAAC BOWE, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improve ments in Boiler-Furnaces, of which the following is a description, reference being had to the accompanying drawings, forming a part of this specification, in which- Figure l is a longitudinal sectional View of my improved furnace, including a side View of a boiler incloscd within a suitable setting. Fig. 2 is a vertical sectional view of said boiler and f'i11m1ce,iaken upontheline 2 2, Fig. l, and viewed in the direction of the arrow there shown. Fig. 3 is a front view in detail of said furnacevdoor, 'from which the draft-regulator has been removed. Fig. 4L is an enlarged elevation, in detail, ofa portion ofthe boiler-front, showing my improved automatic appliances for regulating the admission of air above the grate. Fig. 5 is an enlarged side View, in detail, of said automatic regulating apparatus. Fig. 6 is a transverse vertical sectional view, in detail, of said door and aportion ofthe automatc appliance for regulating the same.

Fig. 7 is an enlarged detail view, in section, of my improved dash-pot constituting a part of said regulating mechanism; and Fig. 8 is an enlarged detail View, partly in section, of a 3o portion ofthe furnace-door and hinge, including the mechanism immediately connected therewith for closing it.

Like letters of reference indicate like parts in the diil'erent iigures.

It is well recognized among those skilled in the art of building and operating furnaces that in order to save fuel and produce complete combustion the conditions must be such as at all times to supply the relative quantity of air 4o to the fuel to form the proper chemical union and to mingle said air with the evolved gases at a temperature sufficiently high to insure their combination. To accomplish this end various means have been devised for uniformly and continuously feeding the fuel to the furnace, in order that the character of the gases given off may be constant and unchanging and thus proportioned to an even and regular draft. While this has been attended with more or less 5o success in different forms, yet objections have been found, among others, that the cost of pre paring the fuel for proper continuous feeding has been so great as to render this method undesirable, while without such preparation it is more or less impracticable to maintain an even and thin tire over the entire grate, so as to uniformly heat the boiler.

My invention has for its object to overcome these difficulties and to so construct a boilerfurnace, in combination with suitable auto- 6o matic appliances, that the same may be fed at intervals in the usual Way, and that by means of said automatic appliances a volume oi' air, or air and steam, may be admitted to the tire above the grate in sufficient quantity to properly commingle and chemically combine with the more volatile hydrocarbon gases iirst evolved, and to be gradually decreased or shut off in proportion as the demand therefor becomes lessened or ceases to exist, so that what 7o are known as coolingdrafts of air may be prevented.

A further object is to so arrange and com struct the bridge-wall of said furnace with reference to the grate and boiler-shell that a sufficient degree of heat may be maintained at all times to complete the combustion of the gases before the products thereof are admitted to the boiler-dues, while at the same time the heat in contact with the boiler-shell is ren- So dered uniform throughout its entire length, which permits said shell to expand evenly, thus preventing the straining of the seams and obviating a wellknown cause of explosion. Moreover, I desire to so construct said furnace as to prevent the formation of eddies therein.

I accomplish said objects substantially in the manner hereinafter more particularly de scribed, and definitely pointed out in the claims. 9o

In the drawings, A represents the furnace wall or setting, while B is an ordinary tubular boiler supported therein in the usual Way.

C represents a grate of any approved form, which is preferably somewhat inclinedy toward g5 the rear.

D indicates a bridge-wall, the main portion of which I construct at or about the height of the grate, from whence it is carried back to the rear of the boiler, as clearly shown in Fig. 1. roo

At or about a distance of one-quarter or one-I third of the length of the grate(more or less) I build up a portion, D', Fig. 2, of said bridgewall in the form of an inverted arch, which is preferably about the thickness in proportion to the length of said bridge-wall, asindicated in Fig. l. A space, E, Figs. l and 2, uniform in width, is provided for the passage of the heat between the bridge-wall and boilershell, while said wall is pierced with two or more tubular iiues, F, through which the main portion of the products of combustion pass, and which are intended to concentrate the heat, and serve, in connection with other applianccs, hereinafter described, to complete the combustion of the gases. The number and size of said dues should vary in proportion to the area of the boiler-tubes. ,A space, D2, be-

v tween the rearof the grate and the beginning of said combustion-filles, is provided, in'order that the oxygen of the air admitted above the grate may thoroughly connningle with the gases before the latter have time to escape to the iiues and thus pass off unconsunied. I provide two or more tubular openings, G, Fig. 1, corresponding in number tothe lues in the bridge-wall and directed toward the same, re-

spectively, into which l insert steam-jet nozzles G', Figs. 1 and 5, which are smaller than the tubes G, S0 that an annular space is left around the former for the admission of air to the furnace. with a steampipe, G2, in direct communication with the boiler. The flow of steam in said pipe is regulated by a Valve, G3, which is operatedin the manner hereinafter described.

H is a cylinder or dash-pot loosely suspended from a bracket, h, which permits said cylinder to swing in the arc of a circle. Said cylinder is provided with a piston, H', Fig. 7, having an opening, h', therein, which is covered upon the under side of thc piston by a check-'valve, Zr". To said cylinder is attached a hollow piston-rod, H, open at the top, but closed at the bottom by a screw-cap, h, to which is loosely attached asmallsupplcmental piston-rod, J, attached to a loose piston, J', within said tube. Said rod should be so at tached to the cap hf that the screwing or unscrewing of the latter may serve to gradually move the piston up or down, so as to wholly expose or cover an opening, h4, within said tube. Upon the lower end of the piston-rod H2 is attached a ring, h5, which is in turn loosely secured to a sleeve, k, mounted upon an arm, K, rigidly attached to a rockshaft, K', extending across the furnace-front and secured intbearings 7c' 7c', Fig. 4. The sleeve k is adjustable upon the arm K, and is secured in any desired position thereon by means of a set-screw, k2, so that the extent to which the shaft is rotated by the movement of the piston may be varied.

The cylinder H is filled with water, oil, or other liquid, and a weight, H3, is attached to the piston-rod to draw the piston down. Ad-

The nozzles G' are connected' justable collars ygg' are likewise attached to said piston-rod by means of set-screws, said collars being provided with projecting pins g2 g3, Figs. 4 and 5, which serve to engage with and operate an arm, G, connected with the stop-cock G2 The extent of movement of said arm, and in turn of said stop-cock, is varied by the position of the pins with relation thereto, so that the valve may be wholly or partially opened or closed, accordingly as the pins are adjusted and the piston-rod reciprocated.

L L arel the upper and L' L' the lower furnace-doors. The draft through the latter is constantly more or less open to supply air beneath the grate; but that in the former is Varied in proportion to the demand therefor to properly support combustion. Each of said main doors L is provided with an inner perforated portion, L2, andan outer supplemental door, L3, mounted upon trnnnions, and having one side, as Z, Fig. G, made heavier than the other, so that its tendency is to open by virtue of its owngravity. Rods Z' Z', loosely pivoted to said supplemental doors and extending upwardly through pcrforations Z2 Z2, are arranged to engage with arms K2 K2, ad- -justably attached to the rock-shaft K'. Rollers Zis Z are provided to prevent friction.

rlhe rock-shaft K' is provided with bevelgears M M, which mesh into like gears M' M', having sleeves m loosely mounted upon the pintles m2 m, Fig. 8, of the door-hinges Z4 Z. Loose rings N N are mounted upon each of said sleeves, to which are rigidly attached arms N' N', having friction-rollers it a upon their free ends, adapted to engage with the doors L. A stud, m, is formed upon each of the sleeves m, which is normally adapted to engage with a shoulder, n', upon the ring, so that as the door Lis opened the gear M' is caused to rotate. By means of handles n2 a2 the arms N' and ring N may be lifted, so that the shoulder and pin are disengaged, when the doors L may be opened without actuating the gears M. Said handles likewise form stops for limiting the backward movement of the doors when opened. The supplemental doors L are provided, also,with adjustable stops L4, which are secured to the door by means of thumb-screws, and are provided with slots, whereby they may be moved up and down, thus limiting the extent to which the door Lii may be opened.

The operation of said mechanism is as follows: Vhen a fresh charge of coal is supplied to the furnace, it is obvious that a large volume of volatile gas is at once given off.' This requires a much greater proportion of air above the grate to insure combustion than is necessary for the fixed carbons. Upon opening the door the gears M M' are rotated by means of the arm N andthe arms K2 are tilted, which permits the gravity-doors L3 to-fall open to their utmost limit..` At the same time the arm K is also tilted, which raises the piston H' to ICO the top of the dash-pot and opens the cock G3,

thus permitting the steam -jets to operate through the openings G. The liquid in the dash-pot passes through the check-valve below the piston; but the weight H3 tends to draw the piston down and to force the liquid through the opening h above the piston,which moves down slowly according to the speed with which said liquid is permitted to pass through said opening, the action thereof being regulated by means of the screw-cap 7a3. Thus the valve G3 is slowly closed, while the rock-shaft is reversed and the arms K2, engaging with the rollers upon the rods Z', gradually close the supplemental doors, thus decreasing the supply of air in regular proportion as the hydrocarbon gases are evolved.

if it is desired to open the door without operating the automatic mechanism, the handle a2 may be lifted, as described. The extent to which thevalvc G3 is opened may also be governed by the position of the pin g3, which may be moved down sufficiently, so that the valve need not be opened at all.

rlhe openings G are placed opposite to the lines F, and as the air or air and steam from said openings and the air from the door L eommingle with the gases before reaching theiiues F, and while said gases are at a temperature above the combustion-point, itis obvious that a complete chemical combination must ensue. Vere this otherwise complete combustion could not be obtained, as itis well known that the highest temperature of the boiler is but about one-half of that required for ignition and one-third of that for complete combustion. As soon, therefore, as the heated gases are brought into direct contact with the boiler shell or tlues, a sufficient degree of heat is absorbed therefrom te reduce the heat of said gases below the point of eombustion,when no further chemical change can take place. By providing the space Di", however, and concentrating the heat immediately in front of and within the flues F, at which points the air is directed, a complete combustion is obtained, as stated.

The space E permits a portion of the heat to pass between the boiler-shell and bridgewall, so that said boiler is uniformly heated throughoutits entirelength. Thebridge-wall D, being built back to the rear end of the boiler, fills the space usually employed as a combustion-chamber, and entirely prevents the formation of eddies, which greatly interfere with the draft, and to that extent impede the action of the furnace.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

l. The combination, in a boiler-furnace, of a bridge-wall, the main portion of which is constructed at or about the height of the grate and carried back to the rear of the boiler, a raised portion in the'form of an inverted arch and provided with combustioniiues and a draft-space between its top and the boiler-shell, and a space between its front and the rear of the grate, with means for introducinga volume ofair above the grate, substantially as and for the purposes set forth.

2. The combination, in a boiler-furnace, of a bridge-wall, the main portion of which is constructed at or aboutV the height of the grate and extended to the rear of the boiler, a higher portion extending upward and conforming to the shape of the boiler, with a sufcient space between the two to permit the ready passage of heat, a space between the rear of the grate and said raised portion, combustion-iiues piercing said raised portion, and means for automaticallyintroducing a large volume of air above the grate upon charging the furnace and for gradually reducing said air-supply, substantially as and `for the purposes set forth.

3. The combination, with a furnace, of the dash-pot H, substantially as described, and

intermediate mechanism for connecting its ration at or near its upper end, and means for partially closing said perforation, in combination with means for operatively connecting said piston-rod with the main and supplemental doors of a furnace, substantially as and for the purposes set forth.

5. In an automatic mechanism for regulating the draft of furnaces, the combination of the doors L, having supplemental gravitydoors mounted in trunnions therein and provided with rods l', a rock-shaft geared to the hinges of said doors and connected by an arm, K, to the piston-rod of a dash-pot, and oscillating arms arranged to engage with the rods Z', for closing the supplemental doors upon the movement of said rock-shaft, substantially as and for the purposes specified.

6. The combination, with a furnace provided with a pipe for injecting steam, and gravity-doors for .admitting air above the grate, of a stop-cock in said pipe connected by an arm with the piston-rod of the dashpot H, a rock-shaft in operative connection with said piston-rod, arms thereon adjusted IOO IIO

to engage with rods loosely attached to said gravity-doors, and gears for connecting said rock-shaft to the hinges of the main doors, substantially as and for the purposes set forth.

7. The combination, with the doorL and sleeve m, having a stud upon its lower end, of the adjustable ring N, having an arm, N', in normal engagement with the face of said door, whereby said ring may be raised and the door opened without operating said au- ISO tornatic draft mechanism, substantially as the furnace, substantially as and for thc purspecifled. poses set forth.

8. The combination, with a furnace-door, 5 i of the supplemental gravity-door L3, the nor- SAG BO WL' 5 ma] tendency of which is to remain open, and XVitncsscs:

the dash-pot with intermediate mechanism D. H. FLETCHER, for gradually closing thc same after charging DAVID STEVENS. 

